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#include "qlayerfilter.h"
#include "qlayerfilter_p.h"
#include "qlayer.h"
#include <Qt3DCore/qpropertyupdatedchange.h>
#include <Qt3DCore/qpropertynodeaddedchange.h>
#include <Qt3DCore/qpropertynoderemovedchange.h>
#include <Qt3DRender/qframegraphnodecreatedchange.h>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {

QLayerFilterPrivate::QLayerFilterPrivate()
    : QFrameGraphNodePrivate()
    , m_filterMode(QLayerFilter::AcceptMatchingLayers)
{
}

/*!
    \class Qt3DRender::QLayerFilter
    \inmodule Qt3DRender
    \since 5.5
    \brief Controls layers drawn in a frame graph branch.

    A Qt3DRender::QLayerFilter can be used to instruct the renderer as to
    which layer(s) to draw in that branch of the frame graph. QLayerFilter
    selects which entities to draw based on the QLayer instance(s) added to
    the QLayerFilter and as components to Qt3DCore::QEntity.

    QLayerFilter can be configured to select or discard entities with a
    specific QLayer depending on the filterMode property. By default, entities
    referencing a QLayer that is also added to the QLayerFilter are selected.
*/

/*!
    \enum QLayerFilter::FilterMode

    Specifies the rules for selecting entities to draw.

    \value AcceptMatchingLayers
           Accept entities that reference a QLayer added to this QLayerFilter

    \value DiscardMatchingLayers
           Discard entities that reference a QLayer added to this QLayerFilter
*/

/*!
    \property Qt3DRender::QLayerFilter::filterMode

    Holds the filter mode specifying the entities to select for drawing.

    The default value is AcceptMatchingLayers.
*/

/*!
    \qmltype LayerFilter
    \instantiates Qt3DRender::QLayerFilter
    \inherits FrameGraphNode
    \inqmlmodule Qt3D.Render
    \since 5.5
    \brief Controls layers drawn in a frame graph branch.

    A LayerFilter can be used to instruct the renderer as to which layer(s)
    to draw in that branch of the frame graph. The LayerFilter selects which
    entities to draw based on the \l Layer instances added to the LayerFilter
    and as components to the \l Entity.

    The LayerFilter can be configured to select or discard entities with a
    specific \l Layer depending on the filterMode property. By default,
    entities referencing a \l Layer that is also added to the LayerFilter are
    selected.
*/

/*!
    \qmlproperty list<Layer> Qt3D.Render::LayerFilter::layers
    Holds a list of layers specifying the layers to select for drawing.
    \readonly
 */

/*!
    \qmlproperty enumeration Qt3DRender::LayerFilter::filterMode

    Holds the filter mode specifying the entities to select for drawing.

    The default value is \c {LayerFilter.AcceptMatchingLayers}.

    \value LayerFilter.AcceptMatchingLayers
           Accept entities that reference a \l Layer added to this LayerFilter

    \value LayerFilter.DiscardMatchingLayers
           Discard entities that reference a \l Layer added to this LayerFilter
*/

/*!
    The constructor creates an instance with the specified \a parent.
 */
QLayerFilter::QLayerFilter(QNode *parent)
    : QFrameGraphNode(*new QLayerFilterPrivate, parent)
{
}

/*! \internal */
QLayerFilter::QLayerFilter(QLayerFilterPrivate &dd, QNode *parent)
    : QFrameGraphNode(dd, parent)
{
}

/*! \internal */
QLayerFilter::~QLayerFilter()
{
}

/*!
    Add \a layer to the current list of layers
 */
void QLayerFilter::addLayer(QLayer *layer)
{
    Q_ASSERT(layer);
    Q_D(QLayerFilter);
    if (!d->m_layers.contains(layer)) {
        d->m_layers.append(layer);

        // Ensures proper bookkeeping
        d->registerDestructionHelper(layer, &QLayerFilter::removeLayer, d->m_layers);

        // We need to add it as a child of the current node if it has been declared inline
        // Or not previously added as a child of the current node so that
        // 1) The backend gets notified about it's creation
        // 2) When the current node is destroyed, it gets destroyed as well
        if (!layer->parent())
            layer->setParent(this);

        if (d->m_changeArbiter != nullptr) {
            const auto change = Qt3DCore::QPropertyNodeAddedChangePtr::create(id(), layer);
            change->setPropertyName("layer");
            d->notifyObservers(change);
        }
    }
}

/*!
    Remove \a layer from the current list of layers
 */
void QLayerFilter::removeLayer(QLayer *layer)
{
    Q_ASSERT(layer);
    Q_D(QLayerFilter);
    if (d->m_changeArbiter != nullptr) {
        const auto change = Qt3DCore::QPropertyNodeRemovedChangePtr::create(id(), layer);
        change->setPropertyName("layer");
        d->notifyObservers(change);
    }
    d->m_layers.removeOne(layer);
    // Remove bookkeeping connection
    d->unregisterDestructionHelper(layer);
}

/*!
    \return the current list of layers
 */
QVector<QLayer *> QLayerFilter::layers() const
{
    Q_D(const QLayerFilter);
    return d->m_layers;
}

QLayerFilter::FilterMode QLayerFilter::filterMode() const
{
    Q_D(const QLayerFilter);
    return d->m_filterMode;
}

void QLayerFilter::setFilterMode(QLayerFilter::FilterMode filterMode)
{
    Q_D(QLayerFilter);
    if (d->m_filterMode != filterMode) {
        d->m_filterMode = filterMode;
        emit filterModeChanged(filterMode);
    }
}

Qt3DCore::QNodeCreatedChangeBasePtr QLayerFilter::createNodeCreationChange() const
{
    auto creationChange = QFrameGraphNodeCreatedChangePtr<QLayerFilterData>::create(this);
    auto &data = creationChange->data;
    Q_D(const QLayerFilter);
    data.layerIds = qIdsForNodes(d->m_layers);
    data.filterMode = d->m_filterMode;
    return creationChange;
}

} // namespace Qt3DRender

QT_END_NAMESPACE
